Annex
FLUXUS G831ST-HT
C Reference
157
UMFLUXUS_G831ST-HTV1-0EN, 2021-06-01
C
Reference
The following tables provide assistance for the user. The accuracy of the data depends on the composition, temperature
and processing of the material. FLEXIM does not assume liability for any inaccuracies.
C.1
Sound speed of selected pipe and lining materials at 20 °C
The values of some of these materials are stored in the internal database of the transmitter. Column c
flow
shows the type
of sound wave (longitudinal or transversal) used for the flow measurement.
The sound speed depends on the composition and processing of the material. The sound speed of alloys and cast
materials fluctuates strongly. The values only serve as an orientation.
C.2
Typical roughness values of pipes
The values are based on experience and measurements.
material (display)
explanation
c
trans
[m/s]
c
long
[m/s]
c
flow
Carbon Steel
steel, normal
3230
5930
trans
Stainless Steel
steel, stainless
3100
5790
trans
DUPLEX
duplex stainless steel
3272
5720
trans
Titanium
titanium
3067
5955
trans
Copper
copper
2260
4700
trans
Aluminium
aluminum
3100
6300
trans
Cu-Ni-Fe
copper-nickel-iron alloy
2510
4900
trans
material
absolute roughness [mm]
drawn pipes of non-ferrous metal, glass, plastics and light metal
0…0.0015
drawn steel pipes
0.01…0.05
fine-planed, polished surface
max. 0.01
planed surface
0.01…0.04
rough-planed surface
0.05…0.1
welded steel pipes, new
0.05…0.1
after long use, cleaned
0.15…0.2
moderately rusted, slightly encrusted
max. 0.4
heavily encrusted
max. 3
cast iron pipes:
bitumen lining
> 0.12
new, without lining
0.25…1
rusted
1…1.5
encrusted
1.5…3